Rotated Matrix

Link

First, flip the matrix across the middle, and then flip it across it's y=x diagonal.

Full Solution in Java:

 public class Solution {
    public void rotate(int[][] matrix) {
        
        for(int i=0; i< matrix.length; i++){
            for(int j=0; j< matrix[i].length/2; j++){
                int temp = matrix[i][j];
                matrix[i][j] = matrix[i][matrix[i].length-j-1];
                matrix[i][matrix[i].length-j-1] = temp;
            }
        }
        
        int iter = matrix[0].length-1;
        for(int i=0; i< matrix.length; i++){
            iter--;
            for(int j=0; j<=iter; j++){
                int displacement = matrix.length-1-(i+j);
                int temp = matrix[i+displacement][j+displacement];
                matrix[i+displacement][j+displacement] = matrix[i][j];
                matrix[i][j] = temp;
                
            }
        }
        
        
    }
}